The number of lines making the context (i.e., the number of lines that are not part of a range but are in the specified line number context)

Detailed Description

Functionalities for detecting whether a line is in one of the stored line ranges (or in the context of a range).

This also performs some optimization: ranges are stored in a set in ascending order; if we have ranges, e.g., 1-20, 50-70, 100-200, and we check whether 23 is in range, we first check if it's in 1-20, then, since it's not there, we check whether it's in 50-70; it is not, and since the range is 50-70 it makes no sense searching for it in other ranges. The next search will start from range 50-70, since we assume that line numbers are always increasing.